1. Field of the Invention
The present invention relates to a liquid shutoff valve gear installed at an upper portion at inside of a hermetically sealed vessel by providing a function of communicating with outside for exhausting a gas at inside of the vessel in accordance with supply of a liquid.
2. Description of the Related Art
A liquid shutoff valve gear is arranged at, for example, an upper portion of inside of a fuel tank of an automobile or the like and is constituted to communicate with a canister at outside thereof. The liquid shutoff valve gear exhausts an evaporated gas to the canister in accordance with supply of a fuel to inside of the fuel tank. Further, when supply of the fuel reaches a predetermined level, communication with the canister is automatically shut off. Thereby, the liquid shutoff valve gear can detect a fuel amount and prevent the fuel from flowing out. As an apparatus of this kind, there is pointed out a liquid shutoff valve disclosed in JP-A-2005-297787 or the like.
Here, simply explaining of the fuel shutoff valve of JP-A-2005-297787, the fuel shutoff valve is constructed by a constitution including a casing having a valve chamber, a valve body mechanism having a float and a seat member and a spring for opening and closing a path connected to the canister by moving up and down the float in accordance with a liquid level of the fuel of the fuel tank.
When the fuel is supplied to the fuel tank, a fuel vapor stored in accordance with a rise of the liquid level of the fuel at inside of the fuel tank can be escaped to a side of the canister by way of the connecting path of the casing. Further, when the fuel reaches the predetermined liquid level of the fuel, the fuel flows into the valve chamber, thereby, the float is moved up and the connecting path is closed. By such a constitution, the fuel vapor from the fuel tank is escaped and the fuel is prevented from flowing out to outside of the fuel tank.
Now, there is a case in which according to a liquid control valve gear, when a connecting path is closed, a splash of the fuel is blown to an inner side of the connecting path by rapidly closing the valve hermetically. In order to prevent this, according to the apparatus of JP-A-2005-297787, there is constructed a constitution in which a first connecting path and a second connecting path are provided, and a seat member closes the connecting paths in steps in accordance with the rise of the liquid level of the fuel. However, even when the splash of the fuel can be prevented in closing the valve by such a constitution, in a case of rocking the fuel tank by vibration or the like, a small gap is produced between the seat member and the connecting paths, and there is a concern of blowing the splash of the fuel to inner sides of the connecting paths.
Further, in order to prevent the splash of the fuel from being blown as described above, a stop valve of JP-A-8-159318 is constructed a constitution of providing a fuel splash flow out preventing plate. However, according to the stop valve of JP-A-8-159318, when the splash of the fuel flows out by riding over the fuel splash flow out preventing plate, the flowed-out fuel cannot be recovered but flows out to outside of the fuel tank over time.
Further, a liquid shutoff valve gear of JP-A-2003-185046 is provided with a cylindrical portion as in JP-A-8-159318 and is provided with a second opening portion for recovering the flowed-out fuel. However, according to the liquid shutoff valve gear of JP-A-2003-185046, a structure thereof becomes complicated such that it is necessary to provide a shutoff valve for closing the second opening portion other than a float.